Zofia Kielan-Jaworowska - Autobiography*

Roots and Early Years My grandfather’s family comes from the village of Kocin Stary near Częstochowa (southeastern Poland), which was said to have been inhabited by many Kielans, and the people in the area used to say that “the Swedes live there.” According to family legend, we are descended from a Scandinavian prisoner of war, from the times of the Swedish Deluge (1655– 1660). There is a name Kielland in Norway, which could have been changed into Kielan in Poland. However, I have never managed to visit Kocin to explore my family’s roots. My grandfather, Walenty Kielan, went to Podlasie during his military service. After leaving the army he got married in Sokołów Podlaski and settled down there. He worked as a cashier for the revenue service. My grandparents had nine children. Their living conditions were so difficult that Franciszek Kielan, my father, having only completed the four years of elementary school, had to start working at the age of twelve in the office of an examining judge secretary. Initially, his work involved copying petitions, but, at the age of fourteen, he had received enough training (which is hard to believe but true) to become the examining judge’s secretary and manage the office on his own. He went to Suwałki at the age of fifteen to work in the office of the public prosecutor. Being talented, diligent, and well-liked, he was encouraged by the lawyers who employed him to continue his education. They helped him cover the high-school curriculum and to prepare for the extramural high school finals. In 1915, the public prosecutor’s office in Suwałki, along with most other Russian institutions, was evacuated to Russia. The revenue service where my grandfather worked was also evacuated and consequently almost the entire Kielan family moved to Russia. My father passed the extramural high-school finals in Russia and worked in various cities and institutions as a military official in the rank of a chief warrant officer. Having survived the October Revolution, which claimed the lives of his two brothers, he lived to see the fall of 1918 and returned to his homeland with his parents and siblings. My father planned to attend university, but the fate intervened when he was called up for army service at the beginning of 1919. He met my mother, Maria Osińska, in Łuków while he was serving in the army as a second lieutenant. She was descended from duniwassal gentry. Having graduated from a private girls’ high school in Łuków, my mother had just started her first office job. My parents

* Written and translated by Zofia Kielan-Jaworowska, 2009; edited by Hans-Dieter Sues, Smithsonian Institution, 2010.

1 were married in 1922 and moved to Sokołów a year later, where my father worked as an accountant in an agricultural and trade cooperative. My sister Krystyna (Krysia to family and friends) was born in 1924, and I first saw the light of the world on April 25, 1925. In 1926 my father was offered a job as an inspector (i.e., as an accountant) for the Association of Agricultural and Trade Cooperatives in Warsaw, and my parents moved first to Warsaw and later in 1928 to Lublin. I still remember our five-year stay in Lublin quite well. With my mother holding an office job as well my parents started to prosper. My mother was always surrounded by books and there was always something for her to read. She was also a member of a Women’s Sports Club and used to play tennis, ice-skate, and ski. My father, on the other hand, after returning from work, having dinner, and reading a newspaper, used to sit at his desk and work on his first book. It was a textbook entitled Accountancy in an Agricultural Trade Cooperative, which had been commissioned by the Association of Cooperatives. The book proved to be a bestseller because it was bought by cooperatives nationwide that had difficulties with implementing new accounting methods. I have no idea when and where my father learned about accounting, but, at that time, he was already considered an authority on this subject. With considerable royalties from his book my parents bought a piano, and we learned to play this instrument. My sister and I attended a small private elementary school in Lublin, which was run by a friend of my mother from the Sports Club. We moved back to Warsaw in 1934 and lived in Żoliborz, initially in the Warsaw Housing Cooperative, and, from 1937, in an apartment purchased by my parents in the “Fenix” Housing Cooperative at 4 Wilson Square. I remember one funny episode from this time. A group of more than twenty persons from my father’s side, who lived in Warsaw, decided that we should spend the Christmas Eve 1936 together. Krysia and I were against such a large family gathering because we thought it was impossible to maintain a real Christmas Eve atmosphere with such a large group of people. However, we had no say in this matter. On our way to my aunt who had a large apartment on Krucza Street downtown, I took along a textbook in mathematics, a notebook, and a fountain pen. Having arrived at her place, I sat at the farthest corner of the huge table to express my disapproval. With the notebook on my lap under the tablecloth I did all the mathematics assignments for that school year while everybody else was eating Christmas delicacies and singing carols. In 1937 I passed the competitive examination for the Aleksandra Piłsudska Sixteenth National Women’s Gymnasium located on Inwalidów Square in Żoliborz. I remember this exam as a very stressful experience. The last two years before the war passed quickly. As a scout, I attended two scouts camps, and I had reached the age of fourteen when the war broke out. There is yet

2 another reason why the year 1939 was a special time for me. It was at that time that I came to the conclusion that the Roman Catholic faith was illogical and full of contradictions and that I could not believe any of it. Luckily, my parents, although traditional believers, were non- practicing, and thus my refusal to attend church services was readily accepted. Many years later, when my atheism was well established, one of my believer friends said to me with an air of superiority: “Not everybody is capable of experiencing the concept of God.” My response was that it seemed to me that I was capable of experiencing what he called God and which is the universe to me, but I could not accept this concept based on the interpretation by shepherds from the Middle East several millennia ago.

The War Years I spent the Siege of Warsaw in September 1939 with my mother and Krysia in the basement. Father, like the majority of male residents of Warsaw, was away hiking at the time and returned home in October. In the fall of 1939, all high schools, colleges, and universities in the General-Gouvernement were closed on the order of the German authorities. Nevertheless, already in November 1939, I started attending the third grade of an illegal gymnasium, which was called the Clandestine Classes of the Sixteenth National Women’s Gymnasium. The classes were conducted in groups of several people in students’ apartments. In the fall of 1940, our indefatigable headmistress, Janina Lubecka, managed to obtain a permit from the German authorities to open two schools, one for knitting and one for gardening, in our old gymnasium building on Inwalidów Square. There were two curricula in the gardening school. One, accepted by the German authorities, included teaching German and gardening, while the other one, illegal, was a regular high school curriculum. In 1940, Krysia, who was a grade ahead of me, followed our father’s advice and started attending the Cooperative High School, which was one of a few legal business schools in Warsaw. However, a year later she decided to study agriculture at the Warsaw University of Life Sciences (SGGW) and moved to a general high school. Thus, from 1941 Krysia and I went to the same grade of high school at our pre-war gymnasium. It was in the same year that a new classmate, Jana Prot, arrived and we became friends. It soon turned out that Jana had no place to live because her father was in England, her mother and her younger brother lived in a cloister in Laski near Warsaw (well known for its boarding school for blind children), and Jana had just gotten evicted from her place. We took Jana home, offering her to live with us, and our parents agreed to that. At that time we did not know that Jana was Jewish. Some three months later, one of our acquaintances, who had known Jana’s father, told my parents about

3 her descent. My mother told me later that, when they found out about it, she and my father were so nervous that they could not sleep at night. However, they finally decided that “what will be, will be” and Jana remained with us. In the fall of 1942, a seven-year-old girl, Romana Laks, also lived with us for a short time. She and her parents had left the ghetto and she awaited placement in a cloister where she survived until the end of the war. In 1991, the Yad Vashem organization honored my family as the “Righteous among Nations” for the help they offered to Jews during the occupation. During 1942-43, we attended the clandestine classes again and took the high school finals, which all three of us passed in 1943. After the finals, I decided to study biology at the University of Warsaw. Krysia wanted to study agriculture at the University of Life Sciences– SGGW, while Jana attended a nursing school and moved to the school’s dormitory. I attended the Clandestine Classes of the Warsaw University during the academic year 1943-44. I also started volunteer training in the National Zoological Museum on 64 Wilcza Street in the spring, and, in June, I passed my exams in the subjects that were taught there. I bought a German zoology textbook in an antiquarian bookstore, intending to study it during the summer vacation. However, I did not have too much time for studying in July 1944 because we were preparing for the Warsaw Uprising. Since the fall of 1939 I had been a member of the Grey Ranks, whose unit was formed at our gymnasium from the three scouting troops that existed before the war. I took courses in medical aid and received practical training at a hospital. My first insurgent assignment was at a medical aid station at Słowacki Street, which was managed by Dr. Jadwiga Moczulska. I arrived there on the first day of August and asked if I could bring my friend Jana Prot who had already completed a year in nursing school and who was at our house at that moment. Dr. Moczulska agreed, and I ran home the following day and returned with Jana to spend the rest of the Uprising together in Żoliborz and Marymont. After the sanitary station on Słowacki Street was closed we were both assigned to the medic patrol of Lieutenant Kwarciany’s company in the Żoliborz Home Army concentration. We were separated from our Company on September 30 because we were carrying the wounded to the hospital. The Uprising’s hospital has been organized in the large basement of a new building of Teachers’ Housing Cooperative on Słowacki Street. At that time, Żoliborz had surrendered after two months of fighting. The Germans then occupied the hospital and it was impossible to make contact with the Company; so we left along with the civilian population. We were taken to a camp in Pruszków near Warsaw, and we met my mother, who had been separated from father, on their way. After several days in a section of the camp designated for forced labor transports to the Third Reich, all three of us managed to

4 escape from the transport and remain in the General-Gouvernement. Our father found us a few days later, owing to the fact that my parents had previously arranged for a dead letter box in the apartment of my father’s sister, who lived in Błonie near Warsaw. When Warsaw was finally liberated in January 1945 I hiked home from Skierniewice, where I had lived with my parents since the Uprising. Krysia, who had been assigned to the district of Praga (a part of Warsaw situated on the other side of the Vistula River) during the Uprising, had been separated from us all those months. The apartment in Żoliborz had been almost completely destroyed by bombs and was not suitable for living, so I went to the Zoological Museum and stayed there. After the collapse of the Uprising, Warsaw was devastated, but the occupiers inflicted the worst damage after the civilian population had already left the city by systematically burning street after street. Almost all the apartments of the museum employees were destroyed, so we had to live among the closets with collections that survived the war. Initially, we had to work as manual laborers, digging out the collections buried in the yard. The work in the Zoological Museum indirectly helped me in choosing my specialty. There was a huge library in the Museum, which had survived the war. While still in high school, I had become interested in the theory of evolution. With unlimited access to the library, I read several books on paleontology, especially those on the history of the vertebrates and the origin of man, and I decided to become a paleontologist. Before the war all of my senior colleagues who worked in the Zoological Museum had attended lectures in paleontology by Professor Roman Kozłowski and had a very high opinion of him. The University of Warsaw finally started its operations again in the fall of 1945 (Fig. 1). It was at that time that I first met Professor Kozłowski. He supervised my master’s thesis and later my doctoral dissertation, and we collaborated for over thirty years after that. The pre-war departments of Geology and Paleontology, located on the main premises of the University on Krakowskie Przedmieście, were destroyed by fire in September 1939, and the professor held the first lectures in paleontology after the war in a small annex of his apartment at 22 Wilcza Street, in a house belonging to a geology professor, Jan Samsonowicz. Six students of geology and zoology attended those first post-war lectures in paleontology. The Department of Geology was located on the second floor of the same building, in Professor Samsonowicz’s apartment. In those early years, studying at the University of Warsaw was a bit complicated due to the great devastation of the city by the war and the fact that the University had been widely dispersed. However, I was lucky because my bicycle had somehow miraculously survived in our destroyed apartment in Żoliborz and thus I was independent of the still inefficient city

5 transportation. I soon stopped working at the Zoological Museum, because it was impossible to reconcile a permanent job with my studies. Having completed my third year of studies in the spring of 1947, a year before starting my master’s thesis, I was offered a trip to the Świętokrzyskie Mountains by Professor Kozłowski to collect materials for my master’s thesis, which was on Devonian trilobites (extinct marine arthropods of the Paleozoic Era from 390 million years ago). The departments of Paleontology and Geology were moved from Wilcza Street to the pre-war building of the Faculty of Chemistry of the University of Warsaw at 1 Pasteur Street in June 1947. After the departments had been moved I went to the Świętokrzyskie Mountains for the first time and this is how I got started on my first research project in paleontology.

The Early Years as a Paleontologist: The Świętokrzyskie Mountains and Erratic Boulders In 1947, a group of researchers from the Museum of Earth and the National Geological Institute started paleontological excavations, for the first time after the war, in the Świętokrzyskie Mountains. The excavations were supported by Jan Czarnocki, an outstanding geologist, leading expert on the geology of the Świętokrzyskie Mountains, and head of the National Geological Institute. The excavations, in which I was scheduled to participate, were conducted in exposures of Middle Devonian strata, 6 kilometers northeast of Nowa Słupia, in the valley of the Dobruchna River. These exposures had been known in the geological literature as the Grzegowice-Skały Section since the nineteenth century, taking their name from two villages located in the southern and northern parts of the exposures, respectively. The field excavations were under the supervision of Roman Kongiel, a professor of paleontology from Toruń University. In July 1947, Professor Stanisław Małkowski, head of the Museum of the Earth, and Professor Roman Kozłowski departed for the Świętokrzyskie Mountains to get acquainted with the work carried out on this section, and they took me along with them. We went to a summer house of the Czarnockis in Kielce, where we met with great hospitality. After spending two days with Jan Czarnocki visiting the most interesting exposures of Paleozoic formations in the Świętokrzyskie Mountains we went to the village of Skały. The excavations initiated by Professor Kongiel were already well advanced. Professor Maria Rożkowska from Poznań University and a few of her students were also there. The most fossiliferous portion in this profile is a series of soft yellow marls, which are filled with shells of brachiopods, fragments of crinoid stalks, and solitary corals. Two workers dug a ditch,

6 exposing fresh, soft rock, which was carried to the river in buckets. Two boys sat there with sieves and soaked the marl in the running water, so that the yellow sediment suspension that went down the river resembled the one during a flood. The fossils that remained on the sieves were placed on bags and dried in the sun. When the professors had left and I was with the group for two months intending to collect trilobites, I asked Professor Kongiel if any trilobites had already been found during the excavations. Kongiel responded that there were none, and my face fell. If a team of several paleontologists had not been able to find a single trilobite during two weeks of work what were my chances of finding material for my master’s thesis? I started an intensive search the very next day, but, during the first week, neither I nor anyone else managed to find a trilobite. I passed my tension on the whole group, and from that time on everybody looked only for trilobites. However, our efforts remained unsuccessful. On the eighth day, I was lucky to find a trilobite on the surface of a freshly crushed piece of limestone. I found a layer with many fossils and started exploring it. Later I found numerous tiny, rolled-up trilobites in the rinsed yellow marl material. My senior colleague, Henryk Makowski, an excellent fossil hunter, joined us in August for a few days, and it took him only several days to find more trilobites than anyone else had during the previous two months. I collected trilobites from the Grzegorzowice-Skały section for three consecutive summer seasons, and my collection grew to several hundred specimens. I studied one genus for my master’s thesis, leaving the rest of the collected material for my doctoral thesis. Having completed my research I was awarded a master’s degree in 1949. Since the fall of 1948 I had also been employed at the University of Warsaw as an assistant in the Department of Paleontology. There I worked until the end of 1952, teaching classes in paleontology for students of geology and biology. In 1952, the Department of Geology at the University of Warsaw was established and the curriculum was changed to the effect that three-year introductory and two-year master’s courses were introduced. Professor Kozłowski continued to lecture in paleontology for students of geology, whereas I was assigned lectures in paleontology in the three-year curriculum in the Faculty of Biology. The Polish Parliament formally established the Polish Academy of Sciences (PAN) in 1951. The guiding principle of the founding authorities of the Academy in 1952 was to provide outstanding scholars who had survived the war with an opportunity to educate young people and to supervise their scholarly activities. It was at that time that new institutions of the Academy were established, including the Paleozoology Department at the Faculty of Biological Sciences. On January 1, 1953, I commenced work at the Department of the

7 Academy, which was located at the time in the building of the Department of Paleontology of the University. Professor Kozłowski headed both institutions. My transfer to the Polish Academy of Sciences was not without problems. I received a letter from the Human Resources Department of the University in December 1952 whose content I will remember for the rest of my life. The letter read: “We hereby inform you that you have been assigned to the discretion of the Chairman of the Central Geology Office as of January 1, 1953.” I am quoting this letter because its form illustrates the standards of bureaucratic Polish science of the 1950s. It turned out that the Chairman of the Central Office of Geology, in order to build up the staff of the National Geological Institute, conducted a survey among the university employees to find the most suitable candidates for work in the geological service. My name was on the list. After receiving that letter I could not sleep that night trying to imagine how my work would change, and my perspectives for the future and my whole life. Paleontology is at the intersection of two major disciplines of the natural sciences, biology and geology. Studying paleontology as a zoologist, I was primarily interested in evolution, changes in the anatomy of animals throughout their history and their causes, and the reconstruction of the evolutionary history of animal groups. However, paleontology is also an auxiliary science to geology, making it possible to determine the relative age of the strata on the basis of so-called index fossils (i.e., fossils that only occur in particular stratigraphic units) and correlating geological horizons across distant areas on the basis of fossils. Had I been transferred to work in the National Institute of Geology I would have had to do work that was essential for the current needs of geology, and this would have changed the direction of my research completely. It is also important to note that, during the early 1950s, when the aforementioned events were taking place, political terror reigned in many Polish institutions. Thanks to the caring support of Professor Kozłowski, a man of great integrity and kindness who enjoyed much prestige as an eminent scholar, we managed to survive this time of trouble. I had no idea what my fate would have been in another large, more bureaucratic institution. Professor Kozłowski was deeply concerned about the issue of my assignment, and he took the letter I had received to the Secretary of the Section of Biological Sciences of the Academy—a member of the Polish United Workers’ Party (PZPR). Fortunately, through the Secretary’s intervention, the decision of the Chairman of the Central Office of Geology was revoked. Although I had collaborated with the National Institute of Geology for many years and I owe that institution a great deal, I wanted to continue my research under the supervision of

8 Professor Roman Kozłowski and to pursue a biological rather than stratigraphic direction in paleontological research. The fieldwork carried out by us in the Świętokrzyskie Mountains was financed by the National Institute of Geology. This support provided not only the funding for excavation and transport, but also a per-diem allowance for us. In those days it was hard to make ends meet living on the salaries earned as a young researcher. Since the lodgings rented from peasants and life in the Świętokrzyskie Mountains was cheap, saving the daily allowance was a significant contribution to our meager income. In 1949 Jan Czarnocki invited Professor Różkowska and me for another long tour of the Świętokrzyskie Mountains, during which he showed us many exposures of the Upper Devonian and Carboniferous. I conducted my own excavation work there in the following years. I turned over the collection of Late Devonian and Carboniferous trilobites to Halszka Osmólska, my junior colleague and friend, since I was already busy working on another large collection. I was studying a pre-war collection of much older trilobites retrieved from the strata of the Late Ordovician from the Świętokrzyskie Mountains, which had been put at my disposal by Jan Czarnocki in 1950. Czarnocki first found those sediments in Zalesie near Łagów in 1928 and in the same year he noted their presence in the village of Wólka south of the Holy Cross Mountain. In 1939 he made a large collection of Late Ordovician trilobites in Brzezinki north of the Łysogóry Range. When the building of the Institute of Geology on Rakowicka Street went up in flames during the Warsaw Uprising almost all of the paleontological collections made by Jan Czarnocki were lost as well, although the collections from Wólka and Brzezinki survived in the basement where there was no fire. However, the geological profiles and the majority of labels were destroyed. Thus, I had a large collection of beautifully preserved trilobites at my disposal, but I was unable to tell which of the specimens came from the younger layers and which came from the older ones. I knew from Jan Czarnocki that the Ordovician strata in Brzezinki were located at the depth of up to eight meters below the surface. In 1953 (two years after Jan Czarnocki’s death) I began my excavations in Brzezinki, still with financial support from the National Institute of Geology. I employed a master well-digger, who arrived with equipment for digging wells; I also hired a dozen or so workers. In addition, eight students of paleontology and geology doing their training practice participated in the projet. First we dug two orientation shafts to determine the strike and the angle of dip of the strata. Next I drew a line perpendicular to the strike, and shafts were dug every 10 meters along this line, which were then connected under the surface by a gallery, which was cheaper than digging a very deep, about 80 meter long trench. The gallery was 1.5 meters high and its roof was supported with wooden beams so that

9 it would not collapse onto a paleontologist sitting under it and drawing a profile of the wall. While digging a profile under the surface under difficult conditions we were unable to extract every layer separately, so we had to extract every running meter of the rock separately and number it consecutively. Students sat among the series of marl samples extracted this way, which was scattered all over the field, and processed the rock and collected fossils contained in it. The trilobite material collected in Brzezinki amounted to several thousand specimens. The following year I conducted excavations at Zalesie near Łagów, where Late Ordovician rocks also contained trilobites. The entire Late Ordovician trilobite material, with which I had been entrusted and which had been collected by many people since the time before the war, amounted to several thousand specimens. It was in 1952, when my Ph.D. thesis was completed (published in 1954) and I was ready to take my Ph.D. examination, that this degree was replaced, in Soviet fashion, with the degree of Candidate of Science. The regulations concerning titles and scholarly degrees in Poland changed several times throughout my academic career. It took more than a year for the executive regulations to the new act to be implemented, and it was not until December 1953 that the public defense of my thesis could take place. Since this was the first public defense of the Candidate degree at the University (in the case of doctoral defenses, the examination was conducted by a small group comprising the supervisor and the reviewers), it attracted crowds that were not so much interested in trilobites as they were curious to see what such a defense might look like. It was also the time when the habilitation was abolished and assistant professors were nominated. When the original degrees were reintroduced several years later I became a doctor, but when I wanted to be habilitated it turned out to be impossible since I had already been nominated as an assistant professor in 1956 and, according to the new regulations, the degree of assistant professor from previous years was equivalent to that of a habilitated doctor. The situation in Polish science changed following Stalin’s death in March 1953. The political terror decreased, and we were gradually allowed to go abroad. In 1955 I travelled to the Soviet Union for the first time, participating in a trip for young biologists organized by the Polish Academy of Sciences. We visited various biological scientific institutions in the Soviet Union during this trip. The most interesting visit for me and my friend Adam Urbanek was that to the Paleontological Institute of the Soviet Academy of Sciences in Moscow, where we were able to see the exhibits of fossil vertebrates from distant parts of the Soviet Union and from expeditions to Mongolia, which I will describe in the next chapter. However, the most important trip at that time was the one to Sweden and Czechoslovakia, where one can find

10 Late Ordovician horizons of the same age as those in the Świętokrzyskie Mountains and with similar faunas of trilobites. In 1956 I received a scholarship from the Polish Academy of Sciences to visit Scandinavia. My Scandinavian colleagues suggested that while describing trilobites from Poland I should also revise trilobites from the Late Ordovician of Scandinavia. My main workplace was Uppsala. First I visited museums in Sweden, Denmark, and Norway that housed Ordovician trilobites, some of them from nineteenth-century collections. Then I borrowed collections that were of particular interest to me and took them to Uppsala. From Sweden I also went to London to become acquainted with the British trilobite collections. When I returned to Poland after a one-year stay I had almost completed a comprehensive monograph on Late Ordovician trilobites from Poland and Scandinavia, comprising several hundred pages of manuscript text with numerous photos and drawings. I also visited Prague during the summer of 1957 to make a comparative study of trilobites from the same time interval in Czechoslovakia. While collecting trilobites from 1947 to 1954 I almost never had time for a summer vacation as I used to spend the summer months in the Świętokrzyskie Mountains. I made one exception in 1950, when my colleagues from the Mountaineering Club persuaded me to go to Morskie Oko to try mountain climbing. Despite my interest in sports I did not enjoy mountain climbing. This was when I first met Zbyszek Jaworowski, a medical student at Jagiellonian University. We became very close friends and got married in 1958. At the beginning of 1959 I sent the most comprehensive of my works to press (published in 1960), which was devoted to Late Ordovician trilobites from Poland, Scandinavia, and Czechoslovakia. This monograph included descriptions of more than 70 species of trilobites and their anatomical study, including various new species, genera, and families, the definition of new stratigraphic divisions for the Upper Ordovician, and discussions concerning paleogeography. I was in a rush to complete it in January because I was expecting the birth of our child in February 1959—our only son Mariusz Arno was born on February 21. When I decided to become a paleontologist many years ago I wanted to study the evolutionary history of vertebrates. However, there are few vertebrate fossils to be found in Poland and when the professor suggested that I should work on trilobites my experience was not adequate to discuss this proposal with him. However, I have never regretted making this decision. Trilobites are a charming group of arthropods, full of mysteries regarding their origin and affinities. I have always enjoyed studying them. However, after twelve years of studying trilobites and having published six studies on them, I decided that it was the time to change the direction of my research. Thus I had a conversation with Professor Kozłowski in

11 1959 during which I suggested that I would like to return to the old subject of my interest, namely the study of fossil vertebrates. However, the professor made another suggestion that postponed this change in research direction for another few years. We used to extract trilobites from the surrounding rock by means of mechanical preparation. Another method of extracting fossils is by means of chemical treatment, which can be applied when the chemical composition of the fossil differs from that of the rock in which it is preserved. The method of chemical treatment was developed on a large scale by Professor Kozłowski himself, who in the pre-war times used hydrofluoric acid to dissolved siliceous rocks (chert) from the Lower Ordovician (from approximately 480 million years ago) in the Świętokrzyskie Mountains. Kozłowski was famous for extracting graptolites, which were preserved in a condition comparable to that of contemporary animals. This allowed him to undertake a very detailed analysis of their anatomy. The professor proved that this mysterious group of invertebrates belongs to neither the coelenterates, bryozoans, nor plants where they used to be placed, but to the hemichordates, a group related to chordates. Fossils with organic skeletons are not only preserved in siliceous rocks but also in limestones. After the war, when the professor was dissolving Ordovician and Silurian erratic boulders introduced to Poland by Pleistocene glaciers from what are now Scandinavia and Estonia, he also found, in addition to graptolites, other fossils including the jaw apparatuses of marine polychaete worms. After the death of the animal, individual elements of the jaw apparatus usually become separated and they had long been known as “scolecodonts” in the paleontological literature. Complete apparatuses had previously been found only twice. It had remained unknown how individual jaw elements were arranged in the apparatuses, and consequently jaw elements representing the same animal had been described using different genus and species names for each separate element. The professor first found complete apparatuses in the erratic boulders and described three of them in 1956; then he gathered a larger collection of apparatuses and suggested that I undertake their description. I knew that the material was unique, and I accepted his offer. It was much easier to collect additional material than it was in the case of trilobites. There was no longer a need for me to leave for three months every year to do fieldwork. All I needed to do was to take a trip to the Mochty brickyard near Warsaw, which quarried glacial clay for brick-making, and bring back a few dozen kilograms of limestone suitable for dissolving. Two years of intensive search resulted in an impressive collection of nearly a thousand Ordovician and Silurian jaw apparatuses. Jaw apparatuses, extracted from limestone by means of dissolving, just like graptolites and other fossils with organic skeletons, are stored in glycerin in plastic boxes. The technical

12 problem in describing this type of material was due to the microscopic size of the specimens. Nowadays they are illustrated using a scanning electron microscope, which was not yet in common use in the early 1960s. Thus drawings had to be made using a drawing device placed on the binocular or the microscope. However, these specimens tended to float in the glycerin, which increased the time needed to draw them. It took me several years to compile this material and, during that time, I managed to publish a few studies about the previously unknown types of apparatuses. I also visited the Zoological Station in Naples and the Natural History Museum in London to familiarize myself with present-day polychaetes, whose mouths contain similar structures. In 1964, I sent my monograph on polychaete jaw apparatuses to the press (it was published in 1966), and then I changed the direction of my research for a second time.

Paleontological Expeditions to the Gobi Desert of Mongolia Professor Roman Kozłowski retired in 1960. On January 1, 1961 I succeeded him as the head of the Institute of the Academy, which I had managed for 22 years. My friend Adam Urbanek, who, like Professor Kozłowski, studied graptolites, replaced him in his post at the University. Soon after assuming my new duties Professor Kozłowski returned from a session of the PAN Presidium with news about the establishment of the Academy of Sciences in the Mongolian People’s Republic and the signing of a scientific cooperation agreement the following year. He also suggested that this might be an opportunity to organize joint Polish- Mongolian Paleontological Expeditions. I had dreamt about participating in paleontological expeditions to Mongolia ever since my student days. I knew from the literature that from 1922 to 1930 paleontologists from the American Museum of Natural History in New York had undertaken five expeditions to the Gobi Desert in Mongolia and China. Their finds included skulls of the oldest placental mammals from the Cretaceous Period known at that time, eggs and skeletons of dinosaurs, and numerous skeletons of mammals from the Tertiary Period. During the first years after the war we had no contacts with paleontologists in the Soviet Union. It was not until 1949 that we learned about three expeditions to Mongolia organized by the Institute of Paleontology of the Soviet Academy of Sciences in Moscow. Soviet paleontologists organized a reconnaissance expedition to Mongolia in 1946, followed by two large expeditions in the years 1948 and 1949. During those expeditions they discovered dinosaur skeletons in the Nemegt Valley, in the southern part of the Gobi Desert. Their achievements during those expeditions were impressive. Numerous skeletons of large

13 predatory and herbivorous dinosaurs were extracted from Late Cretaceous sandstones. All of these skeletons, except for one that was returned to Mongolia, were housed in Moscow. In 1962 a delegation of the Presidium of the Polish Academy of Sciences (PAN) visited Mongolia to sign an agreement concerning scientific cooperation, and Professor Kozłowski, a member of the delegation, took with him the proposal for a three-year project of Polish-Mongolian Paleontological Expeditions for the years 1963–1965 prepared by me. The project was well received by the presidia of both academies and when the PAN delegation returned they tasked me with organizing the expeditions and assuming their scientific leadership. We sent our first reconnaissance team to Mongolia in 1963, supervised by my late colleague Dr. Julian Kulczyki. In 1964 and 1965, we organized two expeditions, which carried out excavations on a large scale (Figs. 2-6). I was unable to leave the country in 1964 for the entire duration of the expedition (over three months) because I was finishing my monograph on polychaete jaw apparatuses and by sending it to press I wanted to close the period of my research on Paleozoic invertebrates. I asked Professor Kazimierz Kowalski, head of the Systematic Zoology Institute of PAN in Cracow, to lead the expedition and I went to Mongolia for only a month. Kazik Kowalski was an excellent supervisor of the expedition, which gathered a valuable collection of dinosaurs, other reptiles, and Cretaceous and Tertiary mammals. All subsequent expeditions, starting with the one in 1965, were led by me. When each expedition was completed, the paleontological collections gathered by subsequent expeditions were provisionally divided in Ulan Bator between the Polish and the Mongolian partners, and a significant portion was then dispatched to Warsaw by train. Based on later agreements between the academies of both countries, the majority of the dinosaur specimens, especially the holotypes, were to be returned to Mongolia upon completion of the scientific studies. And that is what indeed happened. Only remains of taxa that were represented by more than one specimen in the collections remained in Poland. Mounting major expeditions is a technically complex task, which requires considerable effort as well as the involvement of a large team. In the case of our expeditions, which involved a dozen or so people on the Polish side and a few on the Mongolian side, we had to assemble all the requisite gear and supplies in Warsaw. The supplies required for the excavations included plaster to protect the specimens during transport, packaging, complete equipment for the camp, food for 20 people in the field for three months, a first-aid kit, trucks and small off-road vehicles, and fuel for those vehicles (at that time, there was no high-octane gasoline in Mongolia needed for our excellent Star 66 trucks, which we rented for the

14 expedition from the Truck Manufacturing Company in Starachowice). All supplies, which filled two large freight train cars and an open railway truck for transporting gasoline, were shipped from Warsaw in March to be picked up by our Mongolian colleagues in Ulan Bator in May. The participants of the expedition flew from Warsaw to Ulan Bator in May or June. It took us two weeks in Ulan Bator to take care of all arrangements and to prepare the vehicles for the journey. We usually rented two additional trucks with Mongolian drivers to carry part of the supplies to the capital of the South Gobi ajmak (province) of Dalandzadgad, where we rented a fenced area or a shed to be used as a storehouse for the expedition. Maciej Kuczyński, who had worked for several years in the Institute of Paleobiology, was responsible for the technical organization of the expedition. Kuczyński, an architect by training, an explorer and a speleologist, had a lot of experience in organizing expeditions. If we were to organize a large expedition every year we would not have had time to unpack and to prepare at least a portion of the collection, not to mention studying the materials. This is the reason why we took a break in our expedition schedule in 1966. We again sent groups of three paleontologists for the periods of three weeks to Mongolia in the years 1967, 1968, and 1969. During those “mini-expeditions” we focused on the search for small fossils, especially of mammals and lizards, on surface exposures of the Cretaceous sandstones. We collected many important specimens during that time. After the expedition of 1964, when the materials collected during the expedition arrived in Poland, we started preparing specimens and conducting scientific studies, which will be further discussed in the next chapters. Aside from studying the collections we tried to make the results of our research available to the public. In addition to numerous articles in daily newspapers and popular science magazines, TV and radio broadcasts, books about the expeditions, we also developed an exhibition on “Dinosaurs from the Gobi Desert,” which was scheduled to open in the rented halls of the Palace of Culture in Warsaw in the spring of 1968. The exhibition mainly presented the skeletons of dinosaurs and their reconstructions. It was almost completed when its opening had to be postponed for a few months due to political reasons. March of 1968 was the time of political conflict in the Central Committee of the Polish United Workers’ Party. The students’ protest against the cultural policies of the party was exploited in this conflict. When students protested in the streets, the police chased them away with clubs, and the party organized meetings of the staff at the University and the Academy of Sciences to condemn the students’ protests. One such meeting was organized in the building of the Faculty of Geology, which was also home to the Institute of Paleozoology, for all the

15 employees of the institutions housed there. After statements from the organizers I spoke in the defense of the students. Only two people supported me at that time, Halszka Osmólska from our Institute and Hubert Szaniawski, at that time a Ph.D. student in the Institute of the Geological Sciences of PAN and later the Director of our Institute. It was not before long that I had to suffer the consequences of my actions—the party submitted a petition to the authorities of PAN to have me dismissed as Director of the Institute. The negotiations between the party and the authorities of the Academy took several months, and here is a copy of the minutes from the session of the Scientific Secretariat of PAN on June 21, 1968, which settled the issue with Solomonic wisdom:

“Having heard the information from the Secretary of the Second Section about the attitude manifested by the head of the Paleozoology Institute of PAN, Zofia Kielan- Jaworowska, a corresponding member of PAN, the Scientific Secretariat of PAN decided to authorize the Scientific Secretary to explicitly bring to Professor Z. Kielan-Jaworowska’s notice that the attitude manifested by her during this period is in contradiction with the duties and responsibilities of the head of a PAN Department. However, taking into account Professor Z. Kielan-Jaworowska’s previous impeccable supervision of the Department and her scholarly accomplishments, the Scientific Secretariat has decided to limit its actions to the aforementioned stance.”

We finally opened the exhibition “Dinosaurs from the Gobi Desert” at the Palace of Science and Culture a week later, and it enjoyed great popularity until it closed in 1975. We signed another agreement concerning paleontological cooperation with the Mongolian Academy of Sciences and we organized two other large expeditions in the years 1970 and 1971. We intended to continue the expeditions after 1971, unfortunately this turned out to be impossible. Since 1970 there had been parallel Soviet and Mongolian expeditions in Mongolia. Consequently, the authorities of the Mongolian Academy of Sciences informed me that they were unable to continue our cooperation due to the insufficient number of paleontologists that could participate in both the Polish-Mongolian and Soviet-Mongolian expeditions. When the first collections from the Gobi Desert arrived by train in Warsaw in the fall of 1964 the Institute faced the task of setting up a new preparation laboratory. Although the Institute employed several highly qualified technical staff, this team was too small to prepare the many new skeletons of dinosaurs or to mount them for exhibition. Another task was to

16 prepare skulls of small mammals and lizards from the Cretaceous Period, whose length in many cases did not exceed 2 cm. Preparing such tiny fossils has to be done by highly skilled technicians under a binocular microscope, using thin needles. Finally, since most of the skeletons of the dinosaurs we excavated had to be returned to the Mongolian partners after the scientific analysis we needed to make plaster casts to be able to set them up for our exhibition in Warsaw. We also made casts of the most attractive skeletons for the purposes of an exchange with other paleontological museums around the world as well as for sale. During the expeditions and for several years afterwards we increased the number of the technicians hired in our Department to cope with all those tasks. I remember the time of the expeditions and studying and publishing on the collected fossil material as a time of enthusiastic cooperation among a large team of Polish paleontologists and of great satisfaction in our accomplishments. In 1975 we opened an exhibition of life-sized reconstructions of dinosaurs from the Gobi Desert in the Culture Park in Chorzów (southeastern Poland). The models of those dinosaurs were produced on a small scale by Wojciech Skarżyński, a talented sculptor and technical assistant in our Department under the supervision of paleontologists, and they were subsequently enlarged in concrete by professional sculptors in the Culture Park in Chorzów. This exhibition is still open and it is one of the main attractions of the Culture Park in Chorzów. In 1984, the Institute of Paleobiology took over the exhibition halls from the Institute of Zoology of PAN, which were located in the part of the Palace of Culture that belonged to the Palace of Youth and created a section called the Museum of Evolution. Some of the exhibitions were developed in collaboration with the Museum and the Institute of Zoology of PAN. We opened a permanent exhibition on “Evolution on Land” in the Museum of Evolution in 1985. My late colleague Andrzej Sulimski helped me develop the plan for this exhibition. Moreover, a team of technicians from the Institute cooperated with us throughout this entire period. This exhibition, which is still open to the public, features a significant portion of the finds from our expeditions to Mongolia. The Polish-Mongolian Paleontological Expeditions to Mongolia (1963–1971) are viewed by the scientific community worldwide as some of the greatest paleontological expeditions ever undertaken. During those years, we managed to gather an impressive collection of dinosaurs and other reptiles (turtles, crocodylians, lizards and snakes), eggs of dinosaurs and birds, rare specimens of Cretaceous birds, and a remarkable collection of mammal skulls and skeletons from the Cretaceous Period, remains of plants, Cretaceous

17 freshwater invertebrates, and a rich collection of Tertiary mammals. One of the greatest accomplishments of the expeditions was the discovery of vertebrate fossils in strata below the Nemegt Sandstone, now known as the Barun Gojot Formation. These layers were previously considered devoid of fossils. The excavations of these sediments at Chulsan in the Nemegt Valley during the expeditions in 1970 and 1971 yielded numerous skeletons of dinosaurs, crocodilians, lizards, dinosaur eggs, and, most importantly, many specimens of mammals. The collection of Cretaceous mammals gathered during the expeditions, at the time of the termination of the project, constituted the largest collection of mammal skulls from the Mesozoic Era anywhere in the world. According to the agreement with the Mongolian Academy of Sciences the majority of the dinosaur skeletons, after the completion of the scientific study and preparation of casts in Poland, was returned to Mongolia. Only a small number of the original dinosaur material remained in Poland, accompanied by the collections of lizards, crocodylians, turtles, birds, mammals, and invertebrates. From 1969 to 1984, the principal studies of the materials from the expeditions were published in ten volumes of the monograph series Palaeontologia Polonica, under my editorship and with the collective title “Results of the Polish-Mongolian Palaeontological Expeditions.” A total of 64 papers were published in those volumes. Numerous additional studies about the results of the expeditions, and subsequently also general reviews, often co- authored by foreign scholars, were published in international journals such as Nature, Palaeovertebrata, Zoologica Scripta, Acta Palaeontologica Polonica, Lethaia, Fossils and Strata, Historical Biology, Palaeontology, and other venues. The expeditions to Mongolia opened up an entirely new field of research for us, connected with groups that were previously beyond the scope of our primary research activities. The most valuable studies on dinosaurs include those by Halszka Osmólska and Teresa Maryańska. Both authors soon became leading authorities on this group of animals. Magdalena Borsuk-Białynicka and Andrzej Sulimski studied the unique collection of Cretaceous lizards from Mongolia. Ryszard Gradziński and other geologists who participated in the expeditions made important contributions to the geology of the Gobi Desert, while Kazimierz Kowalski and his colleagues from Cracow mainly studied Tertiary mammals. My own task was the study the unique collection of Cretaceous mammals, from a time when dinosaurs ruled the Earth.

Research on Mesozoic Mammals and Two Years at the Muséum National d’Histoire Naturelle in Paris

18 During our expeditions to Mongolia we collected numerous skulls and postcranial skeletons of mammals from the Cretaceous Period. It used to be generally accepted that during the Mesozoic Era, i.e., two-thirds of their entire history, mammals lived “in the shadow” of dinosaurs. Mammals and dinosaurs first appeared on Earth at approximately the same time, at the end of the Triassic Period, some 220 million years ago. Soon after they appeared dinosaurs reached tremendous dimensions and became rulers of the land, whereas mammals were tiny at that time (the majority of them being the size of a mouse or a rat) and led a nocturnal lifestyle. It is not easy to account for the small dimensions of mammals that lived during the reign of dinosaurs. Mammals are descended from “mammal-like reptiles,” which were a dominant group of vertebrates in the second half of the Carboniferous Period and during the Permian Period (from 299 to 251 million years ago). It is assumed that advanced “mammal- like reptiles” called cynodonts, from which mammals are descended, could have to some extent achieved homeothermy—they were thus equipped with the ability to sustain constant body temperature for a longer period of time, yet had no mechanisms that would quickly remove the surplus of heat. This was not particularly needed in the cold climate. However, at the end of the Permian Period and during the Triassic Period, the climate on Earth became warmer and thus smaller size, which enabled more rapid cooling of the body, were more advantageous. I think that this is the reason why cynodonts were gradually becoming smaller. At the end of the Triassic Period, when mammals were emerging, the temperature increased significantly and thus the only chance of survival was a drastic reduction of size and the shift to a nocturnal lifestyle. The mammals that we know from the Mesozoic Era are typically represented only by individual teeth or fragments of jaws with teeth. However, numerous complete skulls and often skeletons have been preserved in the Cretaceous formations of the Gobi Desert. The collection of mammals extracted by our team from Cretaceous sandstones includes three groups: the most numerous group are representatives of an extinct group of mammals, the multituberculates (Fig. 7), accompanied by less numerous placental mammals and the least common deltatheroids, which are related to marsupials. The material collected during our expeditions provided remarkable new information for each of these groups. While the Polish expeditions to Mongolia were still continuing I set about analyzing the collected material. In 1969 when preparing a perfectly preserved skeleton of a multituberculate from Bajn Dzak I noted the presence of so-called pouch (epipubic) bones in the pelvis, known previously only in monotremes and marsupials. Those bones, contrary to

19 their name, are not connected with a pouch, and subsequent discoveries demonstrated that they were present in all Mesozoic mammals. I published a report on this issue in Nature in 1969. We also published the first issue of the “Results of the Polish-Mongolian Palaeontological Expeditions” in 1969, which consisted of a report from the expeditions, information about the geology of the investigated area, and several detailed paleontological studies, including my own introductory study of the Late Cretaceous placental mammals from Mongolia. However, my primary concern in this first period was the structure of the multituberculate skull, which had previously not been completely investigated. What proved to be of great help when writing the monograph on the skull were my two visits to London, to the laboratory of Professor Kenneth Kermack at the University of London, who studied extinct Mesozoic mammals, especially morganucodonts and triconodonts. Direct comparisons with his materials and the discussions with Kenneth and his co-workers facilitated my interpretation of the new structures that I found in the multituberculate skulls. I also met Professor Percy Butler in London, a famous expert on Mesozoic and primitive contemporary mammals. Percy was very interested in our collection of Cretaceous mammals from Mongolia, and he visited Poland in 1973 for the first time. We wrote a study together, which was published in Nature, in which we suggested that the Cretaceous deltatheroids from Mongolia, previously considered an important group of early placental mammals, are actually related to marsupials. I demonstrated in my subsequent studies that deltatheroids should be treated as a sister-group to marsupials (i.e., descended from the same common ancestor) and this is the generally accepted view at present. We currently group marsupials and deltatheroids together in the Metatheria, whereas placental mammals and related extinct groups constitute the Eutheria. I went to the United States in August 1973 for a six-month stay as a visiting professor at Harvard University. I had been to the US several times before for shorter periods of time, but the stay in Cambridge was particularly interesting to me because two paleontologists investigating Mesozoic mammals worked at the Museum of Comparative Zoology. They were professors Alfred W. Crompton (nicknamed Fuzz by his colleagues) and Farish A. Jenkins, Jr. My duties involved lectures on selected issues in vertebrate paleontology and seminars for doctoral students. During this stay, Fuzz Crompton and I conducted a study on the structure of molar teeth and mode of mastication employed by the oldest placental mammals on the basis of the material from Mongolia.

20 After returning home I worked primarily on the structure of the skull and the postcranial skeleton of Cretaceous placental mammals from Mongolia. The comparison of these materials with the skeletons of the most primitive contemporary placentals was very interesting as it demonstrated which features of the skeleton of contemporary mammals are primitive and which emerged in the course of their evolution. I published a report in Nature in 1975 on the possibility of the occurrence of epipubic bones in early placental mammals, based on the structure of the pubic bones in the Cretaceous placental mammal Zalambdalestes from Mongolia. My assumption about the presence of epipubic bones in early placental mammals was subsequently confirmed by American colleagues, who published a study in 1997 concerning the discovery of epipubic bones in another placental mammal from the Gobi Desert. In the summer of 1976, Professor Jason A. (Jay) Lillegraven from the University of Wyoming in Laramie, suggested to me and to Professor William A. (Bill) Clemens from the University of California at Berkeley that we collaborate on a book on Mesozoic mammals. The idea for this book had developed during a course on Mesozoic mammals for graduate students taught by Lillegraven. The initial project envisaged that the book would be primarily written by the students, but it soon turned out infeasible, so that specialists on the various groups of Mesozoic mammals had to be invited to participate in the project. I started work on the chapters assigned to me in the summer of 1976, and in the fall of that year I visited Laramie for six weeks to work on the book; Bill Clemens came there for two weeks as well. Until that time, students were supposed to have prepared a portion of the book chapters. However, when I arrived it turned out that not everyone had fulfilled their tasks and that some of the chapters were so poorly written that new authors had to be recruited, and those chapters had to be rewritten from scratch. Then, in March of 1977, Jay and Bill came to Poland for a month. We took with us all the literature we needed and left for our cottage in Zdziarka on the Vistula near Czerwińsk. Zbyszek commuted to work in Warsaw and brought us food supplies, because at that time all one could buy in the rural shop in Zdziarka was bread (which was delivered twice a week) and some poor-quality canned food and fruit candy. Surrounded by the peace and quiet of Zdziarka, we finished writing and editing the book, which is entitled Mesozoic Mammals and was published by the University of California Press in 1979. Twelve authors contributed to this book. Although I had not yet started the study of the postcranial skeleton of multituberculates in earnest, the peculiar structure of the pelvic girdle kept me thinking. I published a study in Nature in 1979 demonstrating that the right and the left halves of the

21 pelvis have been firmly fused in the lower part so that they could not be separated during delivery. Such a structure of the pelvis indicated that multituberculates could not have been oviparous. The pelvic girdle in oviparous monotremes is wide and U-shaped when viewed from behind, which makes laying eggs possible, whereas, in the case of multituberculates, it has the form of a narrow V, which makes it impossible for any egg to squeeze through. I concluded that multituberculates were almost certainly viviparous and that they were born at an early stage of development, much as in present-day marsupials. The summer of 1980 was the time of labor unrest along the Baltic coast and agreements with strikers by the ruling communist power. Those changes had great impact on the atmosphere in the country, as well as on the Polish Academy of Sciences (PAN), where preliminary work on changes in the Academy Act was initiated as early as in the fall of 1980. In January 1981, during a session of the PAN Presidium, whose member I was, a Committee of the PAN Presidium for Appeals of Unjust Personnel Decisions during 1968-1980 was created, and Professor Aleksander Gieysztor, Chairman of PAN asked me to assume the leadership of the Committee and I agreed. The Committee worked from January 29 to October 29, 1981. During this period 25 meetings were held and 89 applications were examined. Even though the work on the Committee took me almost an entire year I do not consider this time wasted. This experience made it possible for me to learn about the unusual mechanisms in making personnel decisions in the Academy and to help in making up for the injustices experienced by some people laid off for political reasons, who were subsequently reinstated as a result of our efforts. In November 1981, the PAN Presidium accepted my report on the activities of the Committee and suggested its publication in the journal Polish Science. However, the martial law made the publication impossible. The report was published eight years later in the fifth issue of the 1989 volume of Polish Science, and anybody interested in the report should refer to this publication. Every three or four years paleontologists interested in Mesozoic terrestrial animals and plants organize symposiums on Mesozoic terrestrial ecosystems, the purpose of which is the exchange of information from the study of various groups of terrestrial animals and plants of that era. The first symposium in this series was held in Paris in 1978. Halszka Osmólska and I participated in this symposium, and we decided to organize the second symposium in Poland in 1981. Despite the difficulties that our country experienced at that time, the problems with food supplies etc., we managed to rent a large camping house in Jadwisin by the Zegrzyński Reservoir near Warsaw and organized the symposium attended by 47 participants. We

22 subsequently published a special double issue of Acta Palaeontologica Polonica, which was edited by me and Halszka Osmólska and appeared in 1983. In this volume we collected the full text for the 27 research papers presented during the symposium. In 1981 Zbyszek, at that time a professor of radiobiology at the Central Laboratory of Radiological Protection in Warsaw, received an invitation from the Centre d’Etudes Nucléaires in Fontenay-aux-Roses near Paris for a year-long visit to analyze the record of lead and other heavy metal poisoning among the French population. Poland was still under the martial law, and conditions for research were very difficult. I decided to take one-year leave of absence from my department and to accompany him to Paris. I had visited Paris many times before and I had many friends there. I knew that my colleague Professor Armand de Ricqlès of the Paris University VII had purchased a Jung’s microtome for cutting metal, which he and his colleagues used for sectioning fossil bones. While working on her doctoral thesis, my colleague Cecile Poplin used this microtome to section the skulls of tiny Cretaceous fish and to reconstruct their structure. My dream was to use this microtome to prepare sections of the skull of a multituberculate and to reconstruct its internal structure, which otherwise would be a difficult task. However, I needed a permission from the Polish authorities to travel abroad. During the first half a year of the martial law, trips abroad were almost completely suspended, but in the summer of 1982 the situation was slowly returning to normal. We finally received our passports and visas and, on September 14, 1982, set off for France in our car. Our son Mariusz was completing his studies of American literature at Adam Mickiewicz University in Poznań, but the classes which he had to attend in Poznań were already over. Thus he moved to our house in Warsaw and soon got married. Our stay in France extended to two years, and therefore, at the end of 1982, I sent a letter to the authorities of the Academy of Sciences asking them to remove me from the position of Head of the Department, effective January 1, 1983. My successors in the position were the late Professor Halszka Osmólska, and, after her resignation three years later, Professor Adam Urbanek, who, in turn, was succeeded by Professor Hubert Szaniawski. The stay in Paris was excellent. Zbyszek’s colleagues rented a furnished apartment for us in one of the new blocks on the hills surrounded by trees, overlooking the town of Palaiseau near Paris. Commuting to work by the subway was convenient for me. I was given an office in the Museum of Natural History, which was headed by my old friend Philippe Taquet. My office was the place where the famous philosopher and paleontologist Pierre Teilhard de Chardin wrote his doctoral thesis in vertebrate paleontology many years ago.

23 I brought with me a significant part of the collection of Cretaceous mammal skulls from Mongolia. I selected two well-preserved and undeformed skulls belonging to two distinct multituberculate genera, Nemegtbaatar and Chulsanbaatar, for sectioning using the Jung microtome. Cecile Poplin, who was familiar with the use of the microtome, which called for a number of special tricks, helped me do the sectioning. Thus I offered her co-authorship, which she gladly accepted. Sectioning the skulls using the microtome required organizing the technical equipment. I sectioned the skulls in Armand de Ricqlès’s laboratory at the university, which housed the microtome. The skulls were first embedded in epoxy resin. The surface where the knife cutting the peels moved had to be wrapped on three sides in Scotch tape to prevent the 25-µm-thick sections from rolling. I held the consecutive peels by the protruding edge of the tape and passed them on to the lab assistant, who cut them and placed them in between two slides. Then she glued the slides together and marked them with consecutive numbers. The Jung microtome turned out to be a rather unpredictable machine. On being started after having been turned off it would usually damage the first two peels. Therefore I tried not to turn it off for the entire day. I did not go for déjeuner but instead used to bring a sandwich from home, and I cut the skulls 10 hours a day, standing by the microtome for three full months. The skull of Nemegtbaatar (Fig. 7), which was 36 mm long, yielded 1,370 transverse sections. The next step of the work took me another two months. Every fifth section was photographed at 16 times magnification. The photos form the basis for the drawings that I cut out and which served as the basis for making 2 mm thick wax plates. The lab assistant from the Museum, who had been assigned to help me, heated the wax on an electric device, poured it on my drawings and then rolled it to obtain the thickness of 2 mm. Cecile and I cut those plates according to the drawings and after gluing them together we created a model of the brain, nerves and blood vessels of the head at sixteen-times magnification. We did not make a model based on the sections of the smaller skull; instead, we examined them under a microscope. In order to interpret the structures visible on the sections and in the model I needed the help of an anatomist who was familiar with the embryonic development of the skull in contemporary mammals. I turned for help to Robert (Bob) Presley, a colleague of mine from the Department of Anatomy at Cardiff University. I had known him from several meetings at international scientific conferences and from his visit to our department in Warsaw in the spring of 1980. I offered Bob co-authorship on this study. During my stay in France, Bob

24 visited Paris three times and we both interpreted the obtained material. We sent this three- author monograph on the reconstruction of the internal structure of the skull, especially on the blood vessels and the structure of the brain of multituberculates to the Philosophical Transactions of the Royal Society of London, where it was published in 1986. I would not have been able to complete this study without considerable technical support from both the university and the Museum in Paris. While in Paris I received an invitation from a friend at the American Museum of Natural History in New York, Malcolm C. McKenna, to visit the United States and take part in fieldwork he was conducting at Bug Creek in the state of Wyoming, where the sediments from the latest Cretaceous are located. I applied for the US visa, but the US Consulate in Paris informed me that my application was rejected. The Consul informed me during my visit that as a person previously holding a senior position in the Polish Academy of Sciences I must have been a member of the communist party. I declared that I had never belonged to the party and that he was misinformed, as this was not the rule in the Polish Academy of Sciences and in the schools of higher education in Poland. But even if I had been a member of the communist party, so what? I knew many members of the party who had never had any problems receiving an American visa. After visiting the Consul I called Malcolm who sent an intervention to the Consulate in Paris concerning my case. Two weeks later my visa was granted. My visit to Bug Creek was very interesting because the technique for collecting material was totally different from the one we applied in Mongolia. Collecting mammals and other tiny fossils in the Gobi dessert involved crawling on one’s hands and knees over the exposures and careful observation through a magnifying glass of each, more cemented piece of rock. At Bug Creek soft Cretaceous sediments were excavated by means of an excavator from a distant exposure and transported to the bank of a water reservoir where they were placed into boxes with sieves at the bottom. The participants of the field works would stand in the water knee high and shake the boxes with the sieves and remove silt. The concentrate was then left to dry in the sun. Then, sitting at tables, we would pick fossils, including mammal teeth, from the concentrate. Fragments of jaws or other bones were only rarely found. I also worked on several other projects during my stay in Paris. Since 1982 I had been collaborating with Gisle Fosse, the professor of anatomy in the Faculty of Dentistry at the University of Bergen, who was interested in the microstructure of the enamel in Mesozoic mammals. Gisle visited me in Warsaw in 1982 and took photos of the enamel of Cretaceous multituberculates from Mongolia. Gisle came to Paris in December 1983 with the finished

25 photos and an initial draft of the study. After finally editing our study together we sent it to the British journal Palaeontology, where it was published in 1985. We demonstrated in our study the some of the multituberculates have a rare type of enamel, found nowhere else, with prisms whose diameter is many times larger than in other mammals. We called this type of enamel gigantoprismatic enamel, unlike the enamel with prisms of regular size, which is present only in one, large group of Cretaceous multituberculates and in all other mammals (normal prismatic enamel). In the same year, a study of two American colleagues, who had independently reached the same conclusions, was published. We demonstrated in our study that the prismatic enamel appears only later in advanced forms of the Cretaceous Period, whereas Jurassic multituberculates have non-prismatic enamel. This raised the question which of the two types of enamel is more primitive. One would have to analyze the enamel of multituberculates from the Late Jurassic or Early Cretaceous, but we had no such material. It was not until early 1990s, during my visit to the University of Oslo, that Gisle Fosse and I returned to working on this subject. Many friends from Poland and other countries came to visit us during our two-year stay in Paris. Mariusz’s wife, Monika, visited us in the spring of 1984, and we showed her around Paris and then took her for a skiing trip to the Alps. In June 1984, Zbyszek’s contract with the Centre d’Études Nucléaires ended and we returned to Poland with great memories of the two-year stay in France. During 1980-1989 I served as Vice-President of the International Union of Geological Sciences. I represented paleontology and the countries of Eastern Europe in the Union, but my duties were not onerous. The Executive Committee of the Union met in a different country every year, and I took part in those sessions, trying to do my best, whenever possible, to use them to establish contacts with paleontologists. At the end of January 1986, the meeting of the IUGS was held in Washington. A year earlier a study by Australian paleontologists on a jaw with three molar teeth from an Early Cretaceous monotreme called Steropodon had been published in Nature. This was the first Mesozoic mammal reported from Australia. One of the authors sent me a cast of Steropodon. The authors claimed that its molar teeth were the same as those of the oldest placentals and marsupials (the so-called tribosphenic teeth, which I will discuss in more detail in the last chapter). This interpretation seemed implausible to me. Therefore, I took the cast with me to the US and, after the IUGS meeting in Washington, I went to Cambridge, Massachusetts, where Fuzz Crompton, Farish Jenkins, and I wrote a paper that was published in Nature in 1987. On the basis of the comparison of the teeth we suggested that monotremes

26 are descended from the early ancestors of true mammals (which include placentals and marsupials), but that they diverged from these ancestors probably during the Jurassic Period, before the emergence of tribosphenic teeth.

Eight Years of Work at the University of Oslo In August 1985, the University of Oslo published an advertisement in Nature concerning a competition for the position of professor of paleontology. In 1985 the People’s Republic of Poland was slowly nearing its end, but nobody at that time expected that significant political changes would occur within the next few years. It was a bad time for Polish science, and there was no money for the equipment, scientific literature, and foreign travel. After discussion with Zbyszek, I decided to apply for the position in Oslo. We were familiar with Norway from our previous visits and were impressed by this beautiful country. In September I sent five boxes with all my publications, copies of my diplomas, and other required documents to the Vice-Chancellor of the University in Oslo. The University in Oslo appointed an international search committee consisting of five members to evaluate ten applicants from Norway, Sweden, Denmark, Germany, the United Kingdom, and Poland. The committee completed its deliberations in December 1986, and I was informed that I had been selected. The diploma of appointment was signed by King Olav VI on December 5, 1986 and was sent to me by the Minister of Culture and Science in January 1987. It sounded very dignified and archaic (below in the English translation):

“We, King Olav VI of Norway, make it known that by a Decree of our State Council we have appointed and marked, as we thereby mark and appoint—with the obligation, unaccompanied by a third party, to adapt to meet the duties in the professional realm of the office until the change of the professional duties which shall result from a legal act or King’s act with the Parliament’s acceptance—Professor Doctor Zofia Kielan-Jaworowska to be Professor of Paleontology at the University in Oslo, under conditions resulting from the nomination and within the period stipulated by the Ministry of Culture and Science. We commit her to obey the Constitution of Norway and any other laws. She shall be obedient and faithful to the King of Norway and shall fulfill the duties imposed upon her by the office with reliability and devotion. Granted at the Castle of Oslo on December 5, 1986. Confirmed by our hand and the Seal of the Kingdom. Olav – personal signature of the King of Norway. [Two signatures illegible.]

27 The appointment for Professor Zofia Kielan-Jaworowska.”

Then I received a letter from the Norwegian Ministry of Culture and Science that I was to assume my duties at the University of Oslo on June 1. I went to Oslo for a week in February 1987 to give a lecture and to get acquainted with the working conditions, which proved to be very good. The University covered the costs of transporting furniture from Poland and reserved an apartment in the housing estate for University employees. The salary was much higher than that in Poland. Before leaving Poland Zbyszek and I officially retired from our positions. We decided that I would drive the car and then travel by ferry to Sweden, whereas Zbyszek would sail from Gdańsk to Oslo on a yacht of his own design. Natascha Heintz, a researcher from the Paleontological Museum in Oslo, came to Poland to help me move and drive the car. Natascha and I arrived in Oslo at the beginning of June, and Zbyszek arrived on his yacht a month later. When we came to Oslo it turned out that there were no vacant apartments in the university employees’ housing estate, and we were offered two rooms in the Students’ Dormitory, which I refused. Initially, I stayed at Natascha’s place, and the furniture that had been transported in a truck was stored at the Museum. After a week of intensive search I managed to rent an apartment in a new housing estate on the mountainous northeastern outskirts of Oslo, with a large porch and a beautiful view over the lake, fjords, and mountains. I enrolled in a six-week language course in Norwegian at the International Summer School at the University, and I spent most of my time until the end of July learning the language. After finishing the course and taking an examination I was more or less able to communicate in Norwegian. As planned, Zbyszek arrived on his yacht in June. He got a job in the Institute of Physics at the University, so my life became much easier. For the first eight months, we lived in the apartment that I had rented, but the rent was very high. Soon our Norwegian friends advised us to take a mortgage from a bank and buy our own apartment, since paying the mortgage should not cost more than the rent. Thus, in spring 1988 we moved to our own apartment in the northwestern outskirts of Oslo, in a block that bordered on a forest. We had a view of Oslo in the distance from the porch in the other side of the apartment. We decided to take full advantage of our stay in Norway and to pursue our favorite sport—skiing. Our favorite was the skiing center Trysil, located 200 km from Oslo, where one can stay in separate, fully equipped cottages. We also used to ski in the summer, on a glacier in central Norway. Initially, only Mariusz came for winter skiing with our grandson Alexander, since Monika was pregnant. But then, when our granddaughter Zosia was two-

28 and-a-half years old, Mariusz used to come with Monika and two of their children every winter. They often visited during the summer as well, and we went to Poland at least once a year. The University of Oslo, the largest of the four Norwegian universities, was established in 1811 and was initially located along the main street of the city, Karl Johans gate. It is in the main building of the old section of the university where the Nobel Peace Prize is awarded annually. In 1812 King Frederick bought an estate with an old manor and a garden in the vicinity of the town center in the district of Tøyen, which he bequested to the university, and soon a Botanical Garden was established there. Three huge buildings were built at the end of the nineteenth and the beginning of the twentieth centuries on the premises of the Garden: the Zoological, Botanical, and Geological Museums (also comprising the Mineralogical and Paleontological museums). The government later decided to build a large university center in the district of Blindern. However, it was not until after the war that the majority of buildings were constructed. Large, modern buildings for the institutes of seven faculties rose up quickly during that time. The building with the Institute of Geology was opened to the public in 1958 and then the university geology community underwent a split. Some of the researchers remained in the Museum and others moved to Blindern. The ground floor and half of the first floor of the large Geological Museum in Tøyen are occupied by geological and mineralogical exhibits, whereas the paleontological exhibits are housed in the other half of the first floor. Collections, researchers’ offices, and laboratories are located on the second and third floors. What awaited me in the northern part of the second floor was a renovated large office, which, to my great joy, was equipped with a computer and a printer on a desk by the wall, at that time an uncommon sight in Poland. The Paleontological Museum in 1987 employed, apart from me, four full-time researchers. Professor Emeritus Gunnar Heninsmoen, a renowned trilobite specialist, whom I knew from my first visit to Norway in 1956, used to visit the place as well. I took over the department from him. Studies at the Faculty of Mathematics and Natural Sciences proceed in two stages, comprising three years of college to be completed with the degree of candidate of sciences followed by two years of study to be completed with a master’s degree. Natascha had been conducting lectures in the introductory course of paleontology for many years, for students of geology and paleontology and that is how it stayed, whereas lectures in “advanced paleontology” for postgraduates in paleontology and stratigraphic geology were assigned to me. I conducted the lectures in English until the end of my stay, whereas the language of the

29 seminars was Norwegian. I also supervised postgraduate and doctoral theses in the paleontology of vertebrates, participated in various examinations, served on committees, etc. I soon became Chairman of the Norwegian Paleontological Society, a very informal group whose activity was limited to organizing seminars. Until the end of my stay in Norway I held paleontological seminars in the Museum, which enjoyed high attendance, and I often invited colleagues from other institutes and from abroad as speakers. I was also frequently invited to lecture at the universities of Bergen and Tromsø. In 1989 I was elected a foreign member of the Norwegian Academy of Sciences, which expanded the scope of my activities in the scholarly community of Norway. When I arrived in Oslo I found that the paleontological exhibits in the Museum had been neglected and required complete renovation. In Poland I had gained experience in the art of building exhibits. After I became familiar with the collections I prepared a concept for a new exhibition, but I needed artistic assistance which the Museum was unable to provide. I started searching for an artist to work at the exhibition, and soon a young Pole, Bogdan Bocianowski, a graduate from the Warsaw Academy of Arts, who had married a Norwegian and lived in Oslo, answered my call. Bogdan accepted the job at the Museum and turned out to be a talented painter full of visionary ideas. By means of exchanges and purchases I brought numerous casts of dinosaur skeletons to the Museum, including some from the Institute of Paleobiology in Warsaw. At the beginning of the 1930s, the Museum had received, through exchange with the museum in Brussels, a cast of a skeleton of the large herbivorous dinosaur Iguanodon, which was mounted in a semi-upright (almost vertical) position, based on the views held at that time. After sixty years on exhibit, the plaster cast was damaged, and we therefore made a new cast, on the basis of the old model, in epoxy resin, more light-weight and durable than the previous one. The views regarding the posture of two-legged dinosaurs changed in the 1960s. At present they are reconstructed with the backbone arranged horizontally (as in the case of birds), and only the neck is directed upwards. This is the posture we adopted to set up the skeleton of Iguanodon in the larger exhibit hall, and its official opening took place in February 1993. The modernization of the exhibits was a slow process because we had very few technical workers at our disposal. Nevertheless, we would open a new portion of the exhibits to the public every year. When I was leaving, the new exhibition was nearly complete except for the paleobotanical section, which was completed after my departure. During the first year of my stay in Oslo, I applied to the Norwegian Foundation for Science for a grant, and since 1988 I received grants from the Foundation to conduct my

30 research. I could use those grants to purchase research equipment and literature, spend them on fieldwork, foreign trips for me and the students working with me, and invite foreign research collaborators. Jørn H. Hurum, who had shown interest in paleontology and mineralogy since his formative years, proved to be the most talented of my students. Jørn wanted to specialize in vertebrate paleontology. I suggested to him that he undertake the osteological analysis of serial cross-sections of the multituberculate skulls from Mongolia, which I had sectioned with the microtome in Paris in 1982. The sections contain a large amount of anatomical data, and we had used only part of these data for our monograph in Paris. Using the funds from the first grant I purchased a high-end microscope, which Jørn needed in order to carry out the observations of the skull cross-sections under ultraviolet light. Jørn used these sections in his postgraduate and doctoral theses. I returned to Norway for Jørn’s doctoral defense in 1997 because I had already returned to Poland in 1995. During my stay in Norway I briefly resumed my research on trilobites. In 1988 the Swedish National Foundation of Science invited me to participate in an international committee to assess the results of grants in paleontology and stratigraphy awarded by the Foundation during the previous two years. Members of the committee met in Sweden, and we spent a week visiting research centers in Stockholm, Uppsala, Lund and Gothenburg, where researchers had received grants from the Foundation. A report assessing the outcomes of the grants was drawn up at the end. During my visit to Sweden I met Jan Bergström, whom I had known from the time when I first studied trilobites. Jan asked me if I would like to resume, at least to some extent, my studies on trilobites, and I agreed. The reason for this was that Jan had recently found a new locality with numerous Late Ordovician trilobites in Westergotland, the same area from which I had studied trilobites earlier. He sent me a collection of trilobites to Oslo in 1989, and, in the summer of 1990, we left for Westergotland with a group of several people to visit localities and to collect additional specimens. Jan Bergström, Per Ahlberg from the University of Lund, and I published a review of the Late Ordovician trilobites of the suborder Cheirurina in a Swedish geological journal in 1991. However, I had no time for further studies on trilobites because the material of Mesozoic mammals was waiting for me. As fossils of Mesozoic mammals are small I had encountered no problems in bringing with me a large portion of the Mongolian collection from the Institute of Paleobiology in Warsaw to Oslo. The first project that I approached upon my arrival in Oslo was a study of the collection of placental mammals from the Early Cretaceous of Mongolia, collected by the Mongolian paleontologist Demberlyin Dashzeveg, an old friend of mine. This collection,

31 which comprised numerous jaws with teeth, included the oldest placental mammals known at that time. I photographed them under an electron microscope and prepared drawings. However, before sending the study to the press, I decided to investigate the Cretaceous materials from the former Soviet Union (mainly from Uzbekistan), which had been discovered since the beginning of the 1980s by the talented Russian paleontologist Lev A. Nessov from the University of St. Petersburg. I went to St. Petersburg in May 1988 for a one- week visit, and, after my return, I completed a study with Dashzeveg on Early Cretaceous placental mammals from Mongolia, which we published in the Scandinavian journal Zoologica Scripta in 1989. The cooperation with Lev Nessov, whom I had previously known only from his publications, proved very beneficial. The Mesozoic mammal materials that he collected with his students over many years of fieldwork, although less completely preserved than those from Mongolia, were invaluable for comparisons. Lev Nessov and his group of students conducted paleontological expeditions over several years in the arid regions of Uzbekistan, Kazakhstan, Tajikistan, and Kyrgyzstan, under conditions that are difficult to imagine. The team had no car, so all equipment, food supplies, and even drinking water had to be carried on their backs or in carriages that they pushed. Lev visited Norway several times at my invitation, and we published a number of studies together. The most interesting conclusion was the fact that while only multituberculates, as the only herbivorous mammals, are found in the Early and Late Cretaceous sediments from the Gobi Desert, they are very rare in Uzbekistan and were replaced by herbivorous placental mammals, which we considered (on the basis of their teeth structure) as representatives of the oldest ungulates. We invited the American paleontologist J. David Archibald, a specialist on early ungulate mammals, to work on the specimens with us, and he visited Oslo twice. In 1988 (after Lev Nessov’s tragic, untimely death on October 1, 1995) we published a study on these mammals in the American journal Bulletin of Carnegie Museum of Natural History. During my stay in Norway I continued my cooperation with Gisle Fosse from the University in Bergen. As early as 1871, Sir Richard Owen had first described several species of multituberculates from the sediments of the so-called “Purbeck” of southern England, at that time thought to belong to the Jurassic Period. The “Purbeck” is now considered earliest Cretaceous in age. The fossils described by Owen are housed in the Natural History Museum in London. Furthermore, I found out that Paul Ensom at the County Museum in Dorchester had gathered a sizeable collection of individual mammal teeth by means of screenwashing sediments from the Purbeck over the previous few years. Thus Gisle Fosse and I went to

32 London in 1989 and then on to Dorchester to become acquainted with the collections that were of interest to us. The visit to the County Museum in Dorchester proved to be very fruitful. I borrowed a large collection of isolated multituberculate teeth and took it with me to Oslo, where I took stereoscopic photos under a scanning electron microscope. I discovered representatives of a previously unknown group of early multituberculates in this material. In the two studies, published together with Paul Ensom in Palaeontology in 1992 and 1994, we not only described new forms of Early Cretaceous multituberculates, but also suggested features for a new classification for the oldest representatives of this group. Gisle Fosse was less fortunate. When one takes photos of mammal enamel employing an optical microscope it is necessary to remove about 1 mm of the tooth surface with diluted hydrochloric acid, which has to be rinsed off immediately to avoid further damage to the surface. However, the authorities of the Natural History Museum in London would not let us use this method nor take photos under a scanning electron microscope. Thus, Gisle Fosse, Paul Ensom, and I published only a limited study on this subject, and we could only use material from Ensom’s collection for this project. This study appeared in the papers from the Fifth Symposium on Mesozoic Terrestrial Ecosystems, which my colleagues and I organized in Oslo in 1991. Fifty-seven specialists in terrestrial fauna and flora of the Mesozoic Era from fifteen countries participated in the symposium. It was held in one of the conference hotels located on the hills surrounding Oslo from the north with a fascinating view of the city, mountains, and fjords. I spent most of my stay in Oslo studying the postcranial skeleton of multituberculates, which had only been partially investigated previously. The material collected by the Polish- Mongolian Expeditions included fairly complete skeletons, which were perfectly preserved. I started investigating this material when I was still in Poland in 1978 but then I realized that the study should be conducted in cooperation with a zoologist who is familiar with the musculature of small mammals from that period. I only knew the original studies from previous literature by an Armenian zoologist Professor Petr P. Gambaryan (known to his friends as PP), who had been working at the Institute of Zoology of the Russian Academy of Sciences in St. Petersburg for many years. I consider him to be the leading specialist on the musculature of small mammals. Our cooperation began in 1979 when PP visited Poland for the first time at the invitation from the Institute of Paleobiology. First martial law and later my stay in France postponed our cooperation for a few years. It was not until my move to Norway that I could resume my cooperation with PP, supported by fellowships from the Norwegian Foundation that I obtained for him. Gambaryan visited Norway, including two visits with his wife who helped us with the final technical

33 aspects of the studies. When we were completing our monograph in the summer of 1993 I went to St. Petersburg for a month. Our first study together, published in 1994 in the Scandinavian monograph series Fossils and Strata, concerned the postcranial skeleton and a reconstruction of the limb musculature of multituberculates and their locomotion. We proved in this study that the reconstruction of the tarsus suggested by the American paleontologists Walter Granger and George Gaylord Simpson in 1929 and widely accepted for 65 years was incorrect. In that reconstruction, the calcaneum, which is the most important bone linking the shank to the foot, is shown as if “suspended in air,” without any distal contact with another bone. The only contact that the calcaneum had in its distal portion was with the cuboid bone, adjoined to it aslant from the medial side. If the tarsus had actually been built in this way it would have been very easy to dislocate it. In our reconstruction of the tarsus, the third, fourth, and fifth metatarsals are directed laterally relative to the long axis of the calcaneum, whereas the fifth metatarsal, which diverges the most, contacts the calcaneum, supporting it on the distal side. We also argued that the limbs of multituberculates were not placed under the trunk, as is the case in most mammals, but were directed to the side (abducted) as in monotremes and most reptiles. The second study conducted with Petr Gambaryan was devoted to the reconstruction of the jaw musculature of multituberculates. Paleontologists had previously established that the chewing surfaces of the upper and lower teeth of multituberculates indicate that the mandible moved only in a front-to-back direction (as in rodents). However, cutting food in rodents takes place when the mandible moved forward, whereas, in the case of multituberculates, food is cut when the mandible moves backwards, which is unique among mammals. Perfectly preserved attachment areas of the mandibular muscles made detailed muscle reconstruction possible. We also demonstrated that because of the backward movement of the mandible when slicing food all the muscles moving the mandible are attached much closer to the front of the jaw than is the case in other mammals; this resulted in a change of the proportions of the skull. The last project conducted in Oslo was writing a chapter on all known Cretaceous mammals from Mongolia at the request of the editors of a comprehensive volume entitled The Age of Dinosaurs in Russia and Mongolia. When working on this contribution I invited other authors to contribute: Michael J. Novacek (American Museum of Natural History, New York), Boris A. Trofimov (Paleontological Institute, Moscow) and Demberlyin Dashzeveg (Paleontological Center of the Academy of Sciences, Ulan Bator); all of them had described Cretaceous mammals from Mongolia. The publication of the book, as is so often the case with

34 edited volumes, was delayed for some time, but it was finally published by Cambridge University Press in 2000. I managed to complete the first version of this chapter in 1995 when I still was in Oslo. We were at that time preparing to return to Poland although we regretted to have to leave beautiful Norway and many of our Norwegian friends.

Returning Home and a New Book Zbyszek and I returned to Warsaw on August 15, 1995. Mariusz came to Oslo to help us move and transport our belongings. Two years before our return we had taken out a mortgage from a bank in Norway to build a house, which was to be built in Konstancin on a plot adjacent to the one where Mariusz and his family were building their own house. Prior to leaving Oslo we sold our Norwegian apartment and thus could pay off our mortgage. We developed our own plans for our house in Poland while we were still in Oslo. We planned not only a large office for each of us, but also two guest rooms where colleagues visiting us could stay and work. Zbyszek visited Poland several times during our last year in Oslo for matters related to construction of the house, but, in fact, it was our daughter-in-law, Monika, and her father who supervised the construction of the house. When we arrived the house was ready; all that was missing was the garage and the garden was not yet planted. During my stay in Norway, the former Department of Paleozoology (then Paleobiology) had been transformed into the Institute of Paleobiology of the Polish Academy of Sciences and had obtained the rights to confer not only the degree of a doctor but also that of the habilitated doctor and to apply for a full professor degree. My colleague Professor Hubert Szaniawski now served as the head of the Institute. In 1997, the Institute of Paleobiology finally acquired its own quarters (at 51/55 Twarda St.) and was separated from the University where it had been accommodated for over 45 years of its existence. I was appointed President of the Research Council of the Institute of Paleobiology, but I soon resigned from this post, and, in 1997, I assumed the editorship of the quarterly journal Acta Palaeontologica Polonica, which is published by the Institute. I stayed on as editor until 2007. Although Zbyszek and I had returned to our mother institutes both of us set up our research offices in our house in Konstancin where we had plenty of room for everything we needed to conduct research. I also borrowed from the Institute a collection of Cretaceous mammals from Mongolia and a binocular microscope, whereas a second microscope had been presented to me by the University in Oslo. I also brought home my entire library on Mesozoic mammals. We bought a photocopier and a scanner. We installed a fax machine and soon had access to e-mail.

35 For several years I had planned to write a book about the Mesozoic mammals of the world, but I realized that this task was simply too large for a single person. However, I encountered problems finding possible collaborators. My old friends and co-authors on the previous book on Mesozoic mammals, Jay Lillegraven and Bill Clemens, both declined. David Krause from Stony Brook University, a collaborator on several previous studies, also declined. All of them were committed to other projects or they had some important administrative role that they could not give up. I was unwilling to edit a volume with many authors because I knew how difficult it is to make coverage in such books uniform. Sometimes it is easier to write a chapter rather than edit text written by an uncooperative author. Furthermore, it was important that the co-authors should have the same approach to the evolution of mammals and paleontological methods. Finally, I turned to Richard L. Cifelli, a young and active professor from the University of Oklahoma, who studies Mesozoic mammals. I knew him from my visits to the US and greatly appreciated his skills, initiative, and diligence. Rich Cifelli enthusiastically accepted my offer. We soon realized that since both of us studied primarily mammals from the Late Jurassic and Cretaceous periods we would need a third co-author who is a specialist on the oldest mammals from the Triassic and Early Jurassic periods. We chose a young Chinese scientist, Zhe-Xi Luo, working at the Carnegie Museum of Natural History in Pittsburgh, who was an expert on the origin and early evolution of mammals. Luo was one of the first Chinese students who had been allowed to study abroad as a consequence of Deng Xiaoping’s reforms. He arrived in the United States in 1982 as a 24- year-old student of paleontology. I first met him in 1983 when I visited Bill Clemens at the University of California at Berkeley; Bill supervised Luo’s doctoral dissertation. Our paths often crossed since then because Luo, just like me, studies Mesozoic mammals. Initially, Chinese students were supposed to return to their homeland after completing their graduate studies. However, in April 1990, several months after the Tiananmen Square massacre, President Bush decreed that some eighty thousand Chinese citizens who faced possible persecution in their homeland could remain in the United States. Luo and his wife, who has a doctorate in chemistry, were part of this group. Zhe-Xi Luo, just like Rich Cifelli, was enthusiastic to work with me on the book. In May 1999, we signed a contract with Columbia University Press in New York for a book with three authors—Zofia Kielan-Jaworowska, Richard L. Cifelli and Zhe-Xi Luo—and entitled Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure. The contract stipulated completion of the manuscript in two-and-a-half years, but it actually took five years

36 to complete the work. During that time, my co-authors would visit Konstancin once or twice a year to work with me on the book (Fig. 8). During this work we concluded that there were a number of unsolved problems concerning the evolution of Mesozoic mammals and that their solution called for additional research. Since the first chapter of the book that I started writing concerned multituberculates I wanted to settle complicated issues concerning the interrelationships of the various lineages in this group. In 1999 Jørn Hurum and I published a study demonstrating that Mongolian multituberculates from the latter half of the Cretaceous Period are members of an endemic suborder, different from contemporaneous forms from North America. We then worked on another study (published in 2001) on the phylogeny and systematics of multituberculate mammals, and I could use the conclusions from this study while writing a comprehensive chapter on multituberculates for the book. Jørn visited Warsaw several times during the preparation of the study, and I paid visits to Oslo as well. P. P. Gambaryan visited me twice. Colleagues from other countries, with whom I had published various papers, came for visits as well. Studies of the three co-authors of the book on the phylogeny of all Mesozoic mammals proved critical. It all started in 1997 when a group of Australian paleontologists led by Tom Rich described a lower jaw of an Early Cretaceous mammals from Australia, which they named Ausktribosphenos. This mammal has three molar teeth (just like placental mammals) of the so-called tribosphenic pattern, typical of primitive placentals and marsupials and of their extinct relatives. The structure of these teeth makes it possible to both cut and crush food, and they were the basis from which subsequently all complicated types of dentition in placentals and marsupials developed. The authors of the Australian study classified Ausktribosphenos as a placental mammal. If true this discovery would have been of great significance because fossil placental mammals older than the Tertiary from Australia had previously been unknown. I discussed this issue with the majority of my colleagues studying Mesozoic mammals, and almost all of them believed that Ausktribosphenos was not a placental mammal, but none of them was interested in writing a critique. We had not yet formally started work on the book, but I already exchanged correspondence on this issue with Rich Cifelli. I suggested to him that we could write a note on the subject of Ausktribosphenos entitled “Alleged Cretaceous placental from Down Under.” Rich Cifelli proofread the first version of the work and sent it to Luo, who provided additional input. We offered co- authorship to Luo, and together we published this note in the Swedish journal Lethaia in 1998. We argued that Ausktribosphenos is different from placental mammals and suggested

37 that it might belong to an early line of mammals, separate from placentals and marsupials. After the publication of our article Tom Rich visited Warsaw to discuss Ausktribosphenos with me. He arrived on Easter Day when we had a family reunion. Just like other foreign colleagues, he stayed at our place and tried to convince all members of our family who knew English that placental mammals originated in Australia. However, I had an impression that he was not completely sure of his arguments, but I could understand that it was difficult for him to withdraw from this point of view after all newspapers in Australia had already been reporting for a year that the oldest placental mammal had been discovered on that continent. In 1999 a study by an American and Madagascar research team described another mammal with three tribosphenic molar teeth from the Mesozoic Era in the Southern Hemisphere, this time from the Jurassic of Madagascar. This discovery lent support to Tom Rich and his colleagues in arguing that placental mammals appeared as early as in the Jurassic Period and that they did not do so in the Northern Hemisphere (the ancient continent of Laurasia) but rather in the Southern Hemisphere (the ancient continent of Gondwana). This issue kept haunting me. Thus, Luo (as first author), Rich Cifelli, and I conducted a cladistic analysis of 55 features of the dentition and the skeleton for 19 taxa of Mesozoic mammals and two present-day taxa, the results of which were published as an article in Nature in 2001. Our analysis demonstrated that tribosphenic teeth of Mesozoic mammals from the Southern Hemisphere are different from the tribosphenic teeth of mammals from the Northern Hemisphere. Thus we suggested that the tribosphenic condition independently evolved twice in the history of mammals, once in the Southern Hemisphere and once in the Northern Hemisphere. We grouped the mammals with tribosphenic teeth from the Southern Hemisphere, and monotremes in a new group Australosphenida, whereas mammals with tribosphenic teeth that emerged in the Northern Hemisphere were classified as a new group Boreosphenida, comprising all contemporary placentals and marsupials and their fossil representatives. The tribosphenic structure of molar teeth was a very advantageous solution to primitive mammals and the natural selection affected its parallel emergence in two different groups. Australosphenids and boreosphenids are only distantly related to each other. In 2002, we published a second, more comprehensive study on this topic in Acta Palaeontologica Polonica, in which we distinguished 275 structural features of mammals and investigated their occurrence in 46 of the best known Mesozoic mammals and in several extant primitive forms. We analyzed the data using specialized computer software, which generated the most probable phylogeny of Mesozoic mammals and the position of three large groups of contemporary mammals: monotremes, marsupials, and placentals among other mammals. In

38 the book, we used this analysis and other studies, which I conducted in cooperation with different foreign colleagues after my return to Poland. We finally submitted the manuscript of our book to Columbia University Press in June 2003 and the book, which is 630 pages in length, was published in October 2004. I was almost 80 at that time.

Postscript Now Zbyszek and I live in a large house with a garden adjacent to the house where Mariusz resides with his family. Our dog Jess, an Alsatian, has the run of the yard, but mainly lies under the table when I write on my computer, or crawls under my bed when she hears thunder. Zbyszek and I work in different fields, but we help each other. I ask him to proofread almost everything I write, and I do the same with his writings. Thus he has good knowledge about my studies and I now know some things about the ionizing radiation, environmental pollution, and climatic change. We watch our two grandsons grow up and get wiser, and we can see how much better their lives are compared to those of our generation and that of our fathers. Our individual time is coming to an end, but that makes no difference. Over the next three billion years evolution will continue to change the biosphere until the Sun burns Earth to ashes. Nevertheless, we have learned to care about the biosphere and to travel to outer space. We are becoming stewards of all living things and are getting closer to understanding the fact that it is our destiny to extend the evolution of life.

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Fig. 1. Portrait of Zofia Kielan- Jaworowska in the early spring of 1945 when the University of Warsaw resumed operations after the war.

Fig. 2. Restored and mounted skeleton of the sauropod dinosaur Opisthocoelicaudia skarzynskii from the locality Altan Ula IV, Nemegt Basin, Mongolia.

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Fig. 3. Excavating the skeleton of Opisthocoelicaudia skarzynskii at Altan Ula IV in 1965. Several ribs and the femur are visible on the left side.

Fig. 4. Polish members of the 1965 expedition at the Altan Ula camp. From left to right: M. Kuczyński, A. Nowiński, W. Skarzyński, E. Rachtan, D. Walknowski, H. Kubiak, T. Maryańska, J. Małecki, R. Gradziński, J. Lefeld, H. Osmólska, M. Łepkowski, Z. Kielan- Jaworowska, J. Kazmierczak, and W. Siciński.

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Fig. 5. Zofia Kielan-Jaworowska in camp.

Fig. 6. Second camp at Altan Ula IV, Nemegt Basin, during the 1965 expedition. The outcrops of Cretaceous strata are visible just behind the camp. The Altan Ula range is in the background.

Fig. 7. Skull and partial postcranial skeleton of the multituberculate Nemegtbaatar gobiensis from the red beds of Khermeen Tsav II, Mongolia.

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Fig. 8. Zofia Kielan-Jaworowska at home in Konstancin, working with Zhe-Xi Luo (left) and Richard Cifelli (right) on the book Mammals from the Age of Dinosaurs (published in 2004).

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